Off camera light source at a 45° angle to the side. As Greg suggests, a white card or a piece of cardboard covered with aluminum foil can be used as a reflector opposite the flash to lessen the "edge" or "sharpness" of shadows.

As long as the flash is on the same axis as the lens, relief details will be hard to see.


I'd say you may be better off using daylight from a south-facing window and reflectors to highlight the works.